Electrophotographic photoreceptor, and image forming apparatus

Abstract

The present invention relates to an electrophotographic photoreceptor having an electroconductive substrate, and a charge transport layer and a charge generation layer formed on the substrate, characterized in that the charge transport layer contains a charge transport material represented by formula (1) and a binder resin, and the mass ratio of the charge transport material to the binder resin is from 5/100 to 45/100: wherein Ar 1 is an arylene group which may have a substituent; each of Ar 2 , Ar 3 , Ar 4 and Ar 5 is an aryl group which may have a substituent; and n is an integer of from 3 to 6.

The invention claimed is: 
     
       1. An electrophotographic photoreceptor, comprising an electroconductive substrate, a charge transport layer, and a charge generation layer formed on the substrate,
 wherein: 
 the charge transport layer comprises a charge transport material represented by formula (1) and a binder resin, and the mass ratio of the charge transport material to the binder resin is from 5/100 to 45/100: 
 
       
         
           
           
               
               
           
         
         Ar 1  is an arylene group which may have a substituent; 
         each of Ar 2 , Ar 3 , Ar 4  and Ar 5  is an aryl group which may have a substituent; 
         n is an integer of from 3 to 6; 
         the charge generation layer comprises oxytitanium phthalocyanine, such that the oxytitanium phthalocyanine is crystalline oxytitanium phthalocyanine showing peaks at Bragg angles (2θ±0.2°) of 9.5°, 24.1° and 27.3° in an X-ray diffraction spectrum by CuKα ray; and 
         the electrophotographic photoreceptor has a half decay exposure in a range of from 0.089 to 0.096 (μJ/cm 2 ) and VL in a range of from 27 to 63 (−V). 
       
     
     
       2. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 1 . 
     
     
       3. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 1 , wherein the image forming apparatus is capable of exposing the electrophotographic photoreceptor to monochromatic light having a wavelength of from 380 to 500 nm to form an image. 
     
     
       4. The electrophotographic photoreceptor according to  claim 1 , wherein n is an integer of from 4 to 6. 
     
     
       5. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 1 , wherein the image forming apparatus is capable of charging the electrophotographic photoreceptor with a charger disposed in contact with the electrophotographic photoreceptor to form an image. 
     
     
       6. An electrophotographic photoreceptor, comprising an electroconductive substrate, a charge transport layer, and a charge generation layer formed on the substrate,
 wherein: 
 the charge transport layer comprises a charge transport material represented by formula (1), a plurality of charge transport materials, and a binder resin, such that a mass ratio of the total mass of the plurality of charge transport materials to the binder resin is from 25/100 to 55/100: 
 
       
         
           
           
               
               
           
         
         Ar 1  is an arylene group which may have a substituent; 
         each of Ar 2 , Ar 3 , Ar 4  and Ar 5  is an aryl group which may have a substituent; and 
         n is an integer of from 3 to 6; 
         the charge generation layer comprises oxytitanium phthalocyanine, such that the oxytitanium phthalocyanine is crystalline oxytitanium phthalocyanine showing peaks at Bragg angles (2θ+0.2°) of 9.5°, 24.1° and 27.3° in an X-ray diffraction spectrum by CuKα ray; and 
         the electrophotographic photoreceptor has a half decay exposure in a range of from 0.088 to 0.098 (μJ/cm 2 ) and VL in a range of from 44 to 53 (−V). 
       
     
     
       7. The electrophotographic photoreceptor according to  claim 6 , wherein the oxytitanium phthalocyanine is crystalline oxytitanium phthalocyanine showing peaks at Bragg angles (2θ±0.2°) of 9.5°, 24.1° and 27.3° in an X-ray diffraction spectrum by CuKα ray. 
     
     
       8. The electrophotographic photoreceptor according to  claim 6 , wherein n is an integer of from 4 to 6. 
     
     
       9. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 6 , wherein the imaging forming apparatus is capable of exposing the electrophotographic photoreceptor to monochromatic light having a wavelength of from 380 to 500 nm to form an image. 
     
     
       10. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 6 , wherein the image forming apparatus is capable of charging the electrophotographic photoreceptor with a charger disposed in contact with the electrophotographic photoreceptor to form an image. 
     
     
       11. An electrophotographic photoreceptor, comprising an electroconductive substrate, a charge transport layer, and a charge generation layer formed on the substrate,
 wherein: 
 the charge transport layer comprises a charge transport material represented by formula (1) and the charge generation layer comprises oxytitanium phthalocyanine, such that the oxytitanium phthalocyanine is obtained by chemical treatment of a phthalocyanine crystal precursor, followed by contact with an organic solvent to obtain oxytitanium phthalocyanine showing main diffraction peaks at Bragg angles (2θ+0.2°) of 9.5°, 24.1° and 27.2° in an X-ray diffraction spectrum by CuKα ray (wavelength: 1.541 Å): 
 
       
         
           
           
               
               
           
         
         Ar 1  is an arylene group which may have a substituent; 
         each of Ar 2 , Ar 3 , Ar 4  and Ar 5  is an aryl group which may have a substituent; 
         n is an integer of from 3 to 6; and 
         the electrophotographic photoreceptor has a half decay exposure in a range of from 0.088 to 0.098 (μJ/cm 2 ) and VL in a range of from 27 to 63 (−V). 
       
     
     
       12. The electrophotographic photoreceptor according to  claim 11 , wherein n is an integer of from 4 to 6. 
     
     
       13. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 11 , wherein the imaging forming apparatus is capable of exposing the electrophotographic photoreceptor to monochromatic light having a wavelength of from 380 to 500 nm to form an image. 
     
     
       14. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 11 , wherein the image forming apparatus is capable of charging the electrophotographic photoreceptor with a charger disposed in contact with the electrophotographic photoreceptor to form an image. 
     
     
       15. An electrophotographic photoreceptor, comprising an electroconductive substrate, a charge transport layer, and a charge generation layer formed on the substrate,
 wherein: 
 the charge transport layer comprises a charge transport material represented by formula (1) and a polyarylate resin: 
 
       
         
           
           
               
               
           
         
         Ar 1  is an arylene group which may have a substituent; 
         each of Ar 2 , Ar 3 , Ar 4  and Ar 5  is an aryl group which may have a substituent; 
         n is an integer of from 3 to 6; 
         the charge generation layer comprises oxytitanium phthalocyanine, such that the oxytitanium phthalocyanine is crystalline oxytitanium phthalocyanine showing peaks at Bragg angles (2θ+0.2°) of 9.5°, 24.1° and 27.3° in an X-ray diffraction spectrum by CuKα ray; and 
         the electrophotographic photoreceptor has a half decay exposure in a range of from 0.092 to 0.095 (μJ/cm 2 ) and VL in a range of from 36 to 43 (−V). 
       
     
     
       16. The electrophotographic photoreceptor according to  claim 15 , wherein n is an integer of from 4 to 6. 
     
     
       17. The electrophotographic photoreceptor of  claim 15 , wherein the binder resin has a viscosity average molecular weight of from 10,000 to 70,000. 
     
     
       18. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 15 , wherein the imaging forming apparatus is capable of exposing the electrophotographic photoreceptor to monochromatic light having a wavelength of from 380 to 500 nm to form an image. 
     
     
       19. An image forming apparatus, comprising the electrophotographic photoreceptor according to  claim 15 , wherein the image forming apparatus is capable of charging the electrophotographic photoreceptor with a charger disposed in contact with the electrophotographic photoreceptor to form an image.